1. Field
The present disclosure relates generally to video encoding and decoding and, more specifically, to techniques for efficient determination of a macroblock's spatial predictability quality with respect to the H.264 specification.
2. Background
An independently decodable intra-coded frame is the most common form of frame that enables random access to the video signal. The MPEG-x and H.26x standards use what is known as a group of pictures (GOP) which comprises an intra-coded frame (also called an I-frame) and temporally predicted P-frames or bi-directionally predicted B frames that reference the J-frame and/or other P and/or B frames within the GOP. Longer GOPs are desirable for the increased compression ratios, but shorter GOPs allow for quicker acquisition and random access. Increasing the number of J-frames will permit quicker acquisition and random access, but at the expense of lower compression.
Previously, to determine a macroblock's spatial intra predictability an exhaustive search or edge detection based algorithms have been used. However, these algorithms are computationally complex and in particular the edge detection based algorithms produce an estimation with a relatively high probability of error.
Known spatial prediction methods in general do not provide a staged approach for minimizing the computational complexities while also providing a relatively low probability of error in the estimation process. Assessing in a computationally efficient manner and with high accuracy the intra predictability of a macroblock is an important component of mode decision algorithms executed by encoders/transcoders.
Thus, there is a need for techniques for efficient determination of a macroblock's spatial predictability quality with respect to the H.264 specification.